Data Item _refine.overall_SU_R_Cruickshank_DPI

General

Item name
_refine.overall_SU_R_Cruickshank_DPI
Category name
refine
Attribute name
overall_SU_R_Cruickshank_DPI
Required in PDB entries
no
Used in current PDB entries
Yes, in about 5.5 % of entries

Item Description

The overall standard uncertainty (estimated standard deviation) of the displacement parameters based on the crystallographic R value, expressed in a formalism known as the dispersion precision indicator (DPI). The overall standard uncertainty (sigmaB) gives an idea of the uncertainty in the B values of averagely defined atoms (atoms with B values equal to the average B value). Na (sigmaB)2 = 0.65 ---------- (Rvalue)2 (Dmin)2 C-2/3 (No-Np) Na = number of atoms included in refinement No = number of observations Np = number of parameters refined Rvalue = conventional crystallographic R value Dmin = maximum resolution C = completeness of data Ref: Cruickshank, D. W. J. (1999). Acta Cryst. D55, 583-601. Murshudov, G. N. & Dodson, E. J. (1997). Simplified error estimation a la Cruickshank in macromolecular crystallography. CCP4 Newsletter on Protein Crystallography, No. 33, January 1997, pp. 31-39. http://www.ccp4.ac.uk/newsletters/newsletter33/murshudov.html

Additional Descriptive Information for Depositors

               The overall standard uncertainty (estimated standard deviation)
               of the displacement parameters based on the crystallographic
               R value, expressed in a formalism known as the dispersion
               precision indicator (DPI).

               The overall standard uncertainty (sigma~B~) gives an idea
               of the uncertainty in the B values of averagely defined
               atoms (atoms with B values equal to the average B value).

                                      N~a~
               (sigma~B~)^2^ = 0.65 ---------- (R~value~)^2^ (D~min~)^2^ C^-2/3^
                                    (N~o~-N~p~)


               N~a~     = number of atoms included in refinement
               N~o~     = number of observations
               N~p~     = number of parameters refined
               R~value~ = conventional crystallographic R value
               D~min~   = maximum resolution
               C        = completeness of data

               Ref: Cruickshank, D. W. J. (1999). Acta Cryst. D55, 583-601.

                    Murshudov, G. N. & Dodson,
                    E. J. (1997). Simplified error estimation a la
                    Cruickshank in macromolecular crystallography.
                    CCP4 Newsletter on Protein Crystallography, No. 33,
                    January 1997, pp. 31-39.

                   http://www.ccp4.ac.uk/newsletters/newsletter33/murshudov.html

Data Type

Data type code
float
Data type detail
float item types are the subset of numbers that are the floating numbers.
Primitive data type code
numb
Regular expression
-?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?

Advisory Boundary Conditions

Minimum Value Maximum Value
0 0.7